Temporary stimulation lead with polymer electrodes and method of manufacture

ABSTRACT

A temporary medical lead in which stimulating electrical energy is transmitted to body tissue through the lead electrodes via ionic conduction within the hydrogel material. The structure of the hydrophilic hydrogel material consists of a porous structure into which conductive salt ions are diffused. In addition the structure of the hydrogel material can be loaded with a single or combination of therapeutic drugs from which is eluted from the electrode&#39;s surface.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority from U.S. ProvisionalApplication Ser. No. 61/218,498, filed Jun. 19, 2009.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related generally to medical stimulation leads.More specifically, the present invention is related to a temporarystimulation lead with polymer electrodes.

2. Background Art

Medical stimulation leads provide a means to deliver electrical energyfrom an implantable medical device such as a pacemaker orneurostimulator to stimulate body tissue. Such leads are complex devicesthat are designed with an intricate network of conductor wires andelectrodes. Medical stimulation leads can be categorized as being eithera permanent medical lead or a temporary medical lead. As the nameimplies, permanent medical stimulation leads are placed in the body forchronic use to provide continuous long-term stimulation to cardiac orneurological tissue. On the other hand, a temporary medical stimulationlead is designed for relatively short term use in the body. Permanentmedical stimulation leads are designed for long term implantation ofabout 6 months or more and are typically constructed with moredurability than temporary medical stimulation leads.

Before a permanent medical lead system is implanted, a temporarystimulation lead is used to screen potential patients for therapyeffectiveness. This saves expense and minimizes the invasiveness of theprocedure to the patient until it can be proven that the system will beefficacious. Previous prior art temporary leads provide monopolarstimulation in an effort to save size and expense. The present inventionprovides a cost effective multi-polar temporary lead with a smalldiameter which creates less trauma to the patient.

Polymeric materials have previously been used to construct medicalstimulation leads. Such leads utilizing polymeric materials aredisclosed in U.S. Pat. No. 7,225,035 to Brabec et al., U.S. Pat. No.6,922,588 to Kranz et al. and U.S. Pat. No. 5,667,615 to Maurer et al.

Brabec et al. in the '035 patent discloses the use of conductivepolymers such as carbon filled silicone, polyacetylene, polypyrrole andpolyanaline for use as an electrode material. Such materials, as statedby Brabec, provide flexibility and allow the electrode to bend in thetight spaces of the coronary vasculature.

Kranz et al. in the '588 patent discloses the use of conductivepolymeric materials that have been specially processed to produce ananisotropic electrical behavior. In the 588 patent, conductive polymericmaterials such as polyacetylene, polyparaphenylene, polyphenylenesulfide, polyparaphenylvinylene, polypyrrole, polyfuran, polythiophen,polyphenylamine, polyethylenedioxythiophen-polystyrene sulfonate andpolyacene, are processed to produce an electrically conductive medicallead (electrode line as stated by Kranz) designed to minimize electricalradial conduction and enhance electrical conduction along the lead'slongitudinal axis. As Kranz states, in column 4, line 32 of the '588patent, “By presetting the respective polymerisation and processingconditions which are to be adapted to the respective individual caseinvolved, it is possible to ensure that the individual polymer chains ofthe intrinsically conductive polymer coaxially oriented in thelongitudinal direction of the electrode line 12 and there is noconductivity worth mentioning in the radial direction.” As will bediscussed in more detail, the present invention is directed to the useof polymeric materials in electrodes where emission of electrical energyin a radial direction is desired.

Mauerer et al. in the '615 patent is directed to a vaginal electrodewith alternating bands of conductive carbon filled silicone andnon-conductive silicone rubber. Mauerer discloses an improved means ofcoupling electrical energy to the electrode through the use ofmechanical tension to secure the lead wires to the polymeric electrodesof carbon loaded silicon rubber.

Unlike Mauerer, however, the temporary medical stimulation lead of thepresent invention utilizes a hydrophilic polymeric hydrogel materialthat acts as both an electrical stimulation electrode and a reservoirfrom which a therapeutic drug is eluted. Electrical energy is radiallyemitted from the hydrogel structure that provides therapeutic electricalstimulation to body tissue. In addition, a therapeutic drug can beemitted from the surface of the hydrophilic hydrogel material from whichit is stored.

Furthermore, the present invention provides multipolar stimulation thatprovides increased control of the electrical stimulation as compared tomonopolar prior art stimulation. In addition to the medical lead'ssimplified construction, the use of the conductive hydrophilic hydrogelmaterial provides a cost effective means to stimulate tissue and elutetherapeutic drugs that provide a pharmacological benefit.

SUMMARY OF THE INVENTION

The present invention comprises a medical device lead that utilizes apolymeric hydrophilic hydrogel material as the electrode structure of atemporary medical lead. The hydrophilic hydrogel electrode operates onthe principal of ionic conduction. Salt ions that are diffused into theporous hydrophilic hydrogel structure act as electrical conductors thattransfer electrical energy from the medical device to targeted bodytissue. The hydrogel material also acts as a vehicle capable of elutinga therapeutic drug. The present invention comprises an elongated leadbody having proximal and distal lead regions through which conductorwires extend through the lead body center from the proximal region tothe distal region.

A series of individually insulated conductor wires contained within theimplantable medical device extend the length thereof from the lead'sproximal region to the distal region of the lead. The strands ofconductor wires are bundled in a cable or coiled form for ease ofmanufacture.

The distal region of the lead is comprised of a series of alternatingbands of electrically conductive and insulating polymers. Thealternating conductive and insulating polymer bands comprising thelead's distal region wrap around the bundle of conductor wire strands.These alternating conduction and insulation polymer bands create aseries of electrically isolated electrodes through which the medicaldevice's electrical energy is transmitted to the targeted tissue. Eachstrand of conductor wire is electrically connected to a single hydrogelconduction band i.e., an electrode. The lead is designed to allow forthe emission of positively and negatively charged electrical energycreating a multipolar lead in which electrical energy delivered throughthe hydrogel electrode is independently controlled by the medicaldevice.

The conductive polymer bands are made from a hydrophilic hydrogelpolymeric material that has been diffused with electrically conductivesalt ions. These salt ions enable the flow of electrical energy via themigration of conductive ions within the material, thus creating anelectrode in which electricity is conductable through the hydrogelmaterial and radially emittable from the electrode surface forstimulating tissue that is in contact with the hydrogel electrode.

The insulation bands located on both sides of the conduction band serveto electrically isolate the hydrogel electrode bands of the presentinvention. In addition to preventing electrical shorting, the isolationbands enable the electrodes to operate and deliver electrical energythat is of an independent magnitude and polarity from each other.

The structure of the hydrophilic hydrogel material can also be loadedwith a therapeutic drug that is eluted from the electrode surfaceproviding a pharmacological treatment.

Therefore, the present invention is a temporary medical stimulation leadwith electrodes made from a hydrophilic hydrogel material that providesboth electrical stimulation and pharmacological treatment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of the present invention of a temporarymedical lead system.

FIG. 2 shows an enlarged perspective view of the distal region of thepresent medical lead.

FIG. 3 illustrates an enlarged cross-sectional view taken along line 3-3of FIG. 2 of the present invention depicting the notched conductor wirein the hydrogel electrode band.

FIG. 4 depicts a cross sectional view taken along line 4-4 illustratingthe notch in the insulation of the conductor wire strand in theelectrode band.

FIG. 5 illustrates an enlarged cross-sectional view taken along line 5-5of FIG. 2 of the present invention depicting a severed conductor wirestrand in the insulation band.

FIG. 6 depicts a perspective view of the present invention with a coiledconductor wire embodiment.

FIG. 7 illustrates an enlarged cross-sectional view taken along line 7-7of FIG. 6 of the present invention depicting a notched wire strand ofthe coiled conductor wire embodiment in the hydrogel electrode band.

FIG. 8 illustrates an enlarged cross-sectional view taken along line 8-8of FIG. 6 of the present invention depicting a gap of space in aninsulation band between a severed wire strand of the coiled wireembodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now referring to the figures, FIG. 1 shows a perspective view of thepresent invention of a medical lead 10 that is intended for temporaryimplantation in a patient. The lead of the present invention is designedto provide, if desired, both electrical stimulation and pharmacologicaltreatment to cardiac, neurological or other targeted tissue.

The medical lead 10 comprises a flexible, elongated lead body 12 havinga thickness and a length comprising a lead proximal region 14 and a leaddistal region 16. As shown in FIG. 2, a longitudinal axis A-A extendsalong the lead body 12. In a preferred embodiment, the lead body 12 hasa diameter that ranges from about 1 mm to about 6 mm and a length thatranges from about 15 cm to about 200 cm. A plurality of individualelectrically insulated conductor wires 18 reside in the lead body 12.The conductor wires 18 extend from the lead proximal region 14 to thelead distal region 16 along the longitudinal axis A-A. The portion ofthe conductor wires 18 located at the lead proximal end 20 areconnectable to a medical device 22 such as the one shown in FIG. 1.

In a preferred embodiment, there are a total of sixteen insulatedconductor wires 18, each made from a wire strand 24 of a preferredmetallic material such as MP35N, titanium, stainless steel or silvercored wire. Surrounding each wire strand 24 is an electricallyinsulative coating 26, preferably made of polyurethane, polyimide,silicone, polytetrafluoroethylene, ethylene tetrafluoroethylene,fluoropolymers and combinations thereof. The insulative coating 26preferably extends along the entire length of each of the wire strands24. Alternately, these insulated conductor wires 18 could be made from aconductive polymer such as polypyrrole or carbon filled silicone.Although it is preferred that the lead body 12 contain sixteen insulatedconductor wires 18, the present invention could be made with more or afewer number of insulated conductor wires 18.

Within the lead distal region 16 are a series of alternating insulationbands 28 and conduction bands 30, as shown in FIGS. 1, 2, and 6. Boththe insulation bands 28 and conduction bands 30 are discrete bands witha length and thickness that reside along longitudinal axis A-A, in whichthe insulated conductor wires 18 pass through. In a preferredembodiment, the insulation bands 28 have a solid insulation body 32 andthe conductor bands 30 have a solid conductor body 34 through which theinsulated conductor wires 18 tunnel therethrough. As shown in the crosssectional view in FIG. 4, four insulated conductor wires 18A, 18B, 18Cand 18D extend along the length of the conductor band 30A. Conductorband body 34A surrounds insulated conductor wires 18A, 18B, 18C and 18D.Alternatively, both the insulation bands 28 and conductor bands 30 canbe constructed with a hollow passageway that allows space for theinsulated conductor wires 18.

In a preferred embodiment, the insulation bands 28 have a preferreddiameter of about 1.5 mm, a length of about 1 cm to about 10 cm and athickness therewithin. It is preferred that the conduction bands 28 havea diameter of about 3 mm, a length of about 1 cm to about 10 cm and athickness therewithin. However, the diameter of both the insulation andconductive bands can range from about 1 mm to about 6 mm.

Also shown in FIG. 1 is an anchor structure 36 comprised of twoprotruding prongs 38A, 38B. The anchor structure 36 is designed so thatthe medical lead 10 can be easily advanced distally into position, butproximal movement is restricted due to the protruding prongs 38A,38B.Prongs 38A,38B are composed of a biocompatible insulative polymer suchas silicone rubber or polyurethane that provide a rigid yet flexiblestructure. The prongs 38A,38B are attached to the exterior of the leadbody 12 at the proximal end of the lead distal region 16 in such amanner that each prong 38A,38B is oriented at an angle of about 20 toabout 40 degrees from longitudinal axis A-A with their terminal endspointed outwardly toward the lead proximal region 14. The prongs 38A,38B of the anchor structure 36 flex downwardly toward the lead body 12.Each of the prongs 38A,38B are curved with a concave backside thatmatches the curved contour of the lead body 12.

FIG. 2 illustrates an enlarged view of the lead distal region 16. Thelead distal region 16 comprises of a series of alternating insulationbands 28A, 28B, 28C, 28D and 28E and conduction bands 30A, 30B, 30C and30D, which act as the electrodes of the lead. Extending through thecenter of these bands 28,30 are a plurality of individually insulatedconductor wires 18. In a preferred embodiment, there is one moreinsulation band 28 than conduction band 30, and the number of conductionbands 30 equals the number of insulated conductor wires 18. For example,it is preferred that there are sixteen conductor wires 18 and sixteenconduction bands 30, each conductor wire 18 being in electrical contactwith the hydrogel material of a respective conductor band 30. Althoughit is preferred that the number of insulation wires 18 equals the numberof conductor bands 30, it is contemplated that multiple insulation wires18 could be electrically connected to a single conduction band 30 toprovide redundancy and a more robust medical lead 10.

In a preferred embodiment, conduction bands 30, including the conductorband body 34, are composed of an electrically conductive hydrophilichydrogel polymer such as a thermoplastic polyurethane elastomer which issold under the trade name of Techophilic and manufactured by LubrizolAdvanced Materials of Wickliffe, Ohio.

The hydrophilic hydrogel polymer is designed to absorb a liquid such asa saline solution. Salt ions from the saline solution incorporate intothe porous hydrogel material structure to provide a means for electricalconduction within the hydrogel material of the conductor band. Prior touse, the medical lead 10 is submerged in saline where it is allowed tosoak for about 10 minutes to about 3 hours. That is so the conductionbands 30 have a sufficient amount of saline and electrically conductivesalt ions diffused in the hydrophilic polymer hydrogel structure.

It is possible, however, that the medical lead 10 could be inserted intothe body without previously soaking the lead in saline. In thissituation, the operation of the medical lead 10 would rely upon thediffusion of ions present in the body into the hydrogel material toprovide electrical conductivity.

In addition, a therapeutic drug can be loaded within the poroushydrophilic structure of the hydrogel material. Prior to insertion ofthe lead into a body tissue, the therapeutic drug is incorporated intothe structure of the hydrogel by either soaking the hydrogel material inthe therapeutic drug or injecting the hydrogel material with thetherapeutic drug, such as with a needle or syringe. The therapeutic drugis then sequentially eluted from the porous structure of the hydrogelmaterial when the conduction band 30 is located at a targeted site. Thiselution of a therapeutic drug provides a pharmacologic benefit inaddition to providing electrical stimulation. Therapeutic drugs areeluted from the hydrogel material of the conductor band 30 to preventand combat infection, and control pain among other therapeutic benefits.Suitable therapeutic drugs include, but are not limited to,beclamethason, baclofen, dexamethosone, coumadin, heparin, theirderivatives and the like.

In a preferred embodiment, the insulation bands 28 are made from abiocompatible electrically insulative material such as polyurethane,polyimide, silicone, polytetrafluoroethylene, Ethylenetetrafluoroethylene, fluoropolymers and combinations thereof.

FIG. 3 is an enlarged cross-sectional view of conductor band 30A. Asshown in the figure, the insulation on the conductor wire 18A is notched40, thus revealing a portion of bare conductor wire 24A. The amount ofremoved insulation 26A could be a relatively small spot or it could havesufficient length in the shape of a band.

Exposing the bare conductor wire 24A to the hydrogel material creates anelectrical connection between the wire 24 and conductor 30. There is onenotched insulated conductor wire 18 per corresponding conductor band 30.By limiting the conductor band 30 to one corresponding notched insulatedconductor wire 18, a multichannel electrode medical lead is created inwhich each conductor band 30 (i.e. electrode) is independentlycontrollable by the medical device 22. Each conductor band 30 iselectrically connected to a single insulated conductor wire 18 andestablishes an independently controllable electrical channel between themedical device 22 and conductor band 30, i.e. electrode.

For example, the present invention may be configured in which a firstconductor band 30A is connected to a first insulated conductor wire 18Avia a notch 40 in the insulation 26A of the first wire 24A, therebycreating a first channel, a second electrode band 30B is connected to asecond insulated conductor wire 18B via a notch 40 in the insulation 26Bof the second wire 24B, thereby creating a second channel, and so forthuntil all the conductor bands 30 are connected to insulated conductorwires 18 via at least one notch 40 in the insulation 26 of a respectiveconductor wire 24, thereby creating independent channels. Therefore, themedical device 22 is capable of independently controlling the amount ofelectrical energy being transmitted to each independent conductor band30.

Although the lead may be produced with any number of electrode channels,it is preferred that the lead have an even number of electrode channelsto allow for a balance of positive and negative electrical charges. Themultiple independent channels of the device make it possible for thelead of the present invention to be multi-polar. A multi-polar lead isone in which both positive and negative electrical energy is conductedand emitted through the conductor bands 30, i.e. electrodes of themedical lead 22.

The insulated conductor wires 18 are electrically terminated within theinsulation bands 28. After the insulated conductor wire 18 has beennotched 40, exposing the bare wire 24 and therefore creating anelectrical connection to the conductor band 30, it is preferably cut orsevered the wire at the next adjacent distal insulation band 28. Inother words, a conductor wire 18 is preferably terminated in the nextinsulation band 28 that is distal to the conductor band 30 radiallyaligned with the notch 40 in that particular wire 18. This constructionis primarily one of ease of manufacturability. Instead of constructingthe lead from conductor wires 18 of different lengths corresponding tothe axial position of their respective conductor bands 30, all of thewires forming the cable or coil, and the like, are of the same length.Then, each wire 24 has its insulation 26 notched 40 in alignment withits conductor band 30 and cut in alignment with the next distal mostinsulation band 28. The severed distal portions of each wire 24 are leftin the lead even though they are no longer electrically connected toanything. This facilitates ease of manufacturability.

Alternatively, the insulated conductor wire 18 can be terminated byending the insulated conductor wire 18 in the distal insulation band 28.

FIG. 4 shows a cross sectional view, taken along line 4-4 of theconductor band 30A. As the figure shows, a series of four insulatedconductor wires 18A, 18B, 18C and 18D are encased in the hydrogelmaterial which comprises the conductor body 34A. Each of the conductorwires 24A, 24B, 24C and 24D has a sheath of insulation material 26A,26B, 26C and 26D surrounding the diameter of the wire 24.

As shown in FIG. 5, in a preferred embodiment, there is a gap 42 inwhich the insulated conductor wire 18A is severed in two distinct wirehalves in an insulation band 28B. A laser is preferably used to ablateand sever the wire 18. The insulated conductor wires 18 are terminatedto prevent electrical shorting at the lead distal end 44.

As shown in FIG. 6, in an alternate embodiment, insulated conductorwires 18 can be bundled in the form of a coil. As previously shown inFIG. 3 in which the insulated conductor wires 18 are bundled in the formof a cable, each of the coiled conductor wires 46 in the alternateembodiment form has a coiled conductor notch 48. The coiled conductorwires 46 are terminated in the insulation bands 28. It should be notedthat the insulated conductor wires 18 in the present invention are notlimited to bundling in the form of a coil or cable but could also bebundled in other forms such as a braid or as a insulated straightconductor wire 18.

FIG. 7 illustrates an enlarged cross-sectional view taken along line 7-7of FIG. 6. This drawing shows a notch 48A in the insulation coating 26of the coiled wire embodiment 46 of the present invention. Similarly tothe cable embodiment, shown in FIG. 3, a section of insulation coating26 is removed from the coiled conductor wire 46, exposing an area ofbare conductor wire 24. This exposed coiled conductor wire 24 forms anelectrical connection path to the conductive hydrogel material of theconduction band 30A.

FIG. 8 illustrates an enlarged cross-sectional view taken along line 8-8of FIG. 6. This drawing shows a gap 50 between two portions of a coiledconductor wire 46. Similar to the cable embodiment shown in FIG. 5, in apreferred embodiment, a coiled conductor wire 46 is electricallyterminated by severing the wire 46 in two. As in the cabled wireembodiment, each coiled conductor wire 46 is electrically terminated inthe insulation band 28. Once the insulation of the coiled conductor wire46 is notched 48, exposing the bare coiled conductor wire it is thenelectrically terminated in the next distal insulation band 28.

In a preferred embodiment, the medical device lead 10 is constructed byfirst twisting the insulated conductor wires 18 in a cable or coiledform. The number of individual insulated conductor wires 18 correspondsto the number of conductor bands 30, i.e., electrodes. For example, fourinsulated conductor wires 18 correspond to four conductor bands 30, i.e.electrodes, eight insulated conductor wires 18 correspond to eightconductor bands 30, i.e. electrodes, and so forth.

Second, the wire insulation material 26 is removed from the conductorwires 18. Preferably a laser is used to ablate the insulation to createa bare, uninsulated spot on the conductor wire 18. Third, alternatingtubes of the polymeric hydrogel conductor tubing and polymericinsulation tubing are placed over the insulated conductor wires 18,whether in a cabled or coiled form.

As previously mentioned, these insulation and conductor tubes can eitherbe solid or hollow. When solid tubes are used, the insulated conductivewires 18 are bored through the material. When using coiled conductorwires 46, it is preferred that a mandrel be placed through the center ofthe coil. Tubes to provide added stiffness and act as a stylet can alsobe located in the center of the coil.

In a preferred embodiment, tubes of the polymeric insulation materialare placed before and after the conductive tubes to provide electricalinsulation and create electrically isolated conductor bands 30.

Third, heat shrink tubing is placed over the assembly and heat treatedat about 200° C. to about 300° C. for about 30 to about 300 minutes.This heat treatment fuses the assembly of insulated conductor wires 18,and conductor and insulation tubes together, thereby creating intimatecontact between the various areas of bare conductor wire 24 andconduction band material. Heat treatment also seals the alternatingconductive and insulation tube segments together. Therefore, thealternating series of insulation bands 28 and conductor bands 30 arecreated.

Prior to use, the medical lead 10 is soaked in a bath of saline totransfer salt ions of the saline solution into the hydrogel structure ofthe conductor bands 30. It is preferred that the medical lead 10 besoaked in the saline bath for about 10 minutes to about 60 minutes.Additionally, the conductor bands 30 of the medical lead 10 can besoaked in or injected with a single therapeutic drug or combination oftherapeutic drugs.

In that manner, the present medical stimulation lead is provided. Thelead is capable of providing electrical stimulation and orpharmacological treatment when used in conjunction with a medicalprocedure intended to beneficially affect a body tissue.

What is claimed is:
 1. A medical lead configured to provide electricalstimulation to body tissue, the medical lead comprising: a) at least oneconductor band composed of a hydrophilic thermoplastic polyurethaneelastomer, the conductor band having a conductor band lumen extendingalong a conductor band length from a conductor band proximal end to aconductor band distal end; and b) at least one insulated conductor wirehaving a conductor wire length extending from a proximal region of thelead, through the conductor band lumen to a distal region of the lead;c) wherein the at least one conductor wire is provided with a notch inits insulation to thereby expose an uninsulated conductor wire lengthwith at least a portion of the notch being radially aligned with theconductor band, and d) a heat treated heat shrink tubing covering the atleast one conductor band to thereby force the conductor band into anintimate electrically conductive contact relationship with at least aportion of the uninsulated conductor wire length at the notch somewherebetween the conductor band proximal and distal ends thereof.
 2. Themedical lead of claim 1 wherein the at least one conductor wire has acut that is distal of the notch and that terminates electricalconductivity at the cut.
 3. The medical lead of claim 1 whereinelectricity is conductible through the at least one conductor bandthrough an ionic conduction.
 4. The medical lead of claim 1 whereinelectricity is conductible through the at least one conductor bandthrough ionic conduction provided by salt ions in a saline solutioninfusible into the conductor band.
 5. The medical lead of claim 1wherein the hydrophilic thermoplastic polyurethane elastomer is loadedwith a therapeutic drug selected from the group consisting ofbeclamethason, baclofen, dexamethosone, coumadin, heparin, theirderivatives, and combinations thereof.
 6. A medical lead configured toprovide electrical stimulation to body tissue, the medical leadcomprising: a) at least a first and a second conductor bands composed ofa hydrophilic thermoplastic polyurethane elastomer, the first and secondconductor bands each having a conductor band lumen extending along aconductor band length between and to respective conductor band proximaland distal ends; b) at least three insulator bands, each insulator bandhaving an insulator band lumen extending along an insulator band length,wherein one of the conductor bands is disposed intermediate two of theinsulator bands to thereby insulate the first and second conductor bandsfrom each other; and c) at least a first insulated conductor wire and asecond insulated conductor wire, each having respective first and secondconductor wire lengths extending from a proximal region of the lead,through the conductor band lumens and the insulator band lumens to adistal region of the lead, d) wherein the first and second conductorwires are provided with respective first and second notches in theirinsulation to thereby expose first and second uninsulated conductor wirelengths with at least a portion of the first and second notches beingradially aligned in a perpendicular orientation to a longitudinal axisof the respective first and second conductor band lengths, and e) a heattreated heat shrink tubing covering the first and second conductor bandsspaced from each other by the at least three insulator bands to therebyforce the first and second conductor bands into an intimate electricallyconductive contact relationship with the first and second uninsulatedconductor wire lengths at theft notches somewhere between the respectivefirst and second conductor band proximal and distal ends thereof.
 7. Themedical lead of claim 6 wherein at least the first and the secondconductor wires each have a cut that is distal of the respective notchand that terminates electrical conductivity at the cut.
 8. The medicallead of claim 7 wherein the cut is radially aligned with one of therespective first and second insulator bands.
 9. The medical lead ofclaim 6 wherein the at least three insulator bands are composed of abiocompatible electrically insulative material selected from the groupconsisting of polyurethane, polyimide, silicone,polytetrafluoroethylene, Ethylene tetrafluoroethylene, fluoropolymersand combinations thereof.
 10. The medical lead of claim 6 wherein theinsulator band length of each of the insulator bands is from about 1 cmto about 10 cm and the diameter of each of the insulator bands is fromabout 1 mm to about 6 mm.
 11. The medical lead of claim 6 wherein theconductor band at least the first and second length of conductor bandsis from about 1 cm to about 10 cm and the diameter of at least the firstand second conductor bands is from about 1 mm to about 6 mm.
 12. Themedical lead of claim 6 wherein electricity is conductible through atleast the first and the second conductor bands through an ionicconduction.
 13. The medical lead of claim 12 wherein the ionicconduction is providable by salt ions in a saline solution that isinfusible into at least the first and the second conductor bands. 14.The medical lead of claim 6 wherein the hydrophilic thermoplasticpolyurethane elastomer is loaded with a therapeutic drug selected fromthe group consisting of beclamethason, baclofen, dexamethosone,coumadin, heparin, their derivatives, and combinations thereof.
 15. Themedical lead of claim 6 wherein the insulation of the conductor wires isselected from the group consisting of polyurethane, polyimide, silicone,polytetrafluoroethylene, ethylene tetrafluoroethylene, fluoropolymersand combinations thereof.
 16. The medical lead of claim 6 configured tobe connectable to a medical device selected from the group consisting ofa pacemaker, defibrillator, and a neurostimulator.
 17. A medical leadconfigured to provide electrical stimulation to body tissue, the medicallead comprising: a) at least a first and a second conductor bandscomposed of a hydrophilic thermoplastic polyurethane elastomer, thefirst and second conductor bands each having a conductor band lumenextending along a conductor band length between and to respectiveconductor band proximal and distal ends; b) at least three insulatorbands, each insulator band having an insulator band lumen extendingalong an insulator band length, wherein one of the conductor bands isdisposed intermediate two of the insulator bands to thereby insulate thefirst and second conductor bands from each other; and c) at least afirst insulated conductor wire and a second insulated conductor wire,each having respective first and second conductor wire lengths extendingfrom a proximal region of the lead, through the conductor band lumensand the insulator band lumens to a distal region of the lead, d) whereinthe first and second conductor wires are provided with respective firstand second notches in their insulation to thereby expose an uninsulatedconductor wire length that is radially aligned with at least a portionof the respective first and second conductor band lengths, and e) a heattreated heat shrink tubing covering at least the first and secondconductor bands spaced from each other by the at least three insulatorbands to thereby force the first and second conductor bands into anintimate electrically conductive contact relationship with at least aportion of the first and second uninsulated conductor wire lengths attheft notches somewhere between the respective first and secondconductor band proximal and distal ends thereof.
 18. The medical lead ofclaim 17 wherein at least the first and the second conductor wires eachhave a cut that is distal of the respective notch and that terminateselectrical conductivity at the cut.
 19. The medical lead of claim 18wherein the cut is radially aligned with one of the respective first andsecond insulator bands.
 20. The medical lead of claim 17 whereinelectricity is conductible through at least the first and the secondconductor band through an ionic conduction.
 21. The medical lead ofclaim 17 wherein the at least three insulator bands are composed of abiocompatible electrically insulative material selected from the groupconsisting of polyurethane, polyimide, silicone,polytetrafluoroethylene, Ethylene tetrafluoroethylene, fluoropolymersand combinations thereof.